Mercury Handling
Guidelines
1. Facts and figures
02
Physical properties of mercury
Chemical symbol
Density Molar mass
Melting point Boiling point
Vapor pressure Mass concentration θ in air (after reaching equilibriuim) Evaoparation rate Solubility of elemental mercury in water
Hg
13.55 g/cm³ (at θ = 25 °C) [1]
200.59 g/mol [1]
234.29 K (-38.86 °C) [1]
629.88 K (356.73 °C) [1]
0.0253 Pa
(at θ = 0 °C) [2]
0.17 Pa
(at θ = 20 °C)
0.391 Pa
(at θ = 30 °C)
0.81 Pa (at θ = 40 °C)
1.69 Pa (at θ = 50 °C)
2.0 mg/m³
(at θ = 0 °C) [2]
13.6 mg/m³
(at θ = 20 °C)
29.6 mg/m³
(at θ = 30 °C)
62.7 mg/m³ (at θ = 40 °C)
126.0 mg/m³ (at θ = 50 °C)
56 µg/(h cm2) • cm² [3]
0.06 mg/L (at θ = 25 °C) [1]
Toxicity
Mercury metal has a liquid state of matter at room temperature (approx. 20 °C) and normal pressure (approx.
1000 hPa).
•Mercury vapor, which is already formed at room
tem­­­­perature, is highly toxic: vapor with a mercury con­
­­­centration exceeding the TLV (threshold limit value) of
0.1 mg/m3 air causes chronic poisoning after prolonged breathing for 5 to 8 hours per day [12]. Despite
the large number of laboratories involved in polarographic/voltammetric work, sensible and proper hand­
ling has ensured that not one single case of mercury
poisoning has been reported to date. The real Hg
con­­centrations measured in the laboratory atmosphere
are consistently far below the TLV.
•Organic mercury compounds are very toxic. Dime­
thyl­­­­mercury is an extremely toxic form of organic mer­
cury, and very small exposures can cause severe and
irre­­
versible delayed neurotoxicity, including death.
Di­­me­­thylmercury is thought to be metabolized to me­­
thyl­­­mercury prior to crossing the blood-brain barrier.
Dimethylmercury is quickly absorbed through intact
skin, and it will penetrate latex or polyvinyl gloves. It is
highly volatile, will readily evaporate, and can be in­­
haled [5].
Mercury and its compounds are toxic since they react
with sulfur-containing enzymes and inactivate them. The
toxicity depends on the chemical and physical state of
the mercury [2, 4–6].
•Metallic liquid mercury is relatively harmless, but it
is readily resorbed through the skin and finds its way
through glandular passages into lower skin regions
where it is oxidized and carried on as a salt.
•The sparingly soluble, inorganic mercury(I) compounds and metallic mercury in the form of a coherent
liquid have low toxicity when taken up orally (but not
through the skin!).
•Mercury(II) compounds are more readily soluble and
therefore much more toxic.
Toxicity to fish: LC50 – Oncorhynchus mykiss (rainbow
trout) – 0.016 mg/L – 96 h [13].
Hg(0)
<
Hg(I)
<
Hg(II)
<
Hg vapors
<
organic Hg
Applications with mercury
Most of the mercury is used in the chloralkali process.
While other important applications are using huge
amounts of mercury, the European demand for mercury
used in polarography is rather small and can be easily
kept in a closed material cycle.
Application
Mercury consumption
Percentage
(tons/year)
Chlor-alkali production
160 - 190
41.2%
Dental amalgams
90 - 110
23.5%
Miscellaneous uses
15 - 114
15.2%
Chemicals
28 - 59
10.2%
Batteries
7 - 25
3.8%
Light sources
11 - 15
3.1%
Measuring equipment
7 - 17
2.8%
Mercury drop electrodes
0.1 - 0.5
0.1%
Switches, relays, etc.
0.3 - 0.8
0.1%
Source: (COWI – Consultancy within Engineering, Environmental Science and Economics, 2008) [8]
Mercury demand in the EU
Chlor-alkali production
Dental amalgams
Hg drop electrodes
Miscellaneous uses
Measuring equipment
Switches, relays, etc.
Light sources
Batteries
Chemicals
03
2. Handling of mercury in the laboratory
04
Several safety rules, described in detail below, must be
observed in the handling of mercury owing to its toxicity.
Working in a fume cupboard
The handling of mercury should, if possible, always be
carried out in a fume cupboard (fume hood). It must be
ensured that no mercury drops are spilled on the floor or
the lab bench and that no mercury evaporates.
Working over plastic trays
Vessels containing mercury must be carried in, or at least
above, rigid seamless trays made of plastic or enamelled
metal. The supplied 6.2711.030 drip pan made of polys­ty­rene is eminently suitable for this.
Collecting spilled mercury drops
Single mercury drops in this drip pan or any other spilled
mer­­­­­­­cury can be bound in a simple manner by amalgamation:
• With silver (Ag): Mercury drop catcher type 6.2406.000
which is included in the scope of delivery of the 797 VA
Computrace.
•With tin (Sn): e.g., the thin tin foil supplied by Merck,
Darmstadt/Germany [1]
•With special laboratory aids: e.g., Mercurisorb-RothTM
from Roth, Karlsruhe/Germany [9]
e.g., Mercury Spill Clean-up kitTM from J. T. Baker,
Phillipsburg, N. J./USA [10]
Do not use a vacuum cleaner or a broom!
Collecting mercury from the measuring vessel
If the MME is used, mercury gathers on the bottom of
the measuring vessel at the end of the determination,
which must be collected for later disposal. This can be
done by collecting the analysis solutions in a large vessel
and then decanting.
Do not use the mercury catcher in the measuring vessel!
Empty reservoir of mercury drop catcher regularly
The storage container of the 6.2406.000 mercury drop
catcher should be emptied regularly and rinsed thoroughly several times. If the mercury drop catcher is used
outside the fume cupboard, keep a minimum safety distance of 50 cm between your head and the mercury trap.
Never leave mercury in open vessels
Mercury must never be left in open vessels. An upper
layer of water or supporting electrolyte in no way suppresses or reduces mercury evaporation.
Store mercury container in fume cupboard
The tightly closed, small, unbreakable mercury container
as well as all parts that come into contact with mercury
must be stored in a fume cupboard, which is always
switched on.
Ventilate laboratory areas well
Rooms where work with mercury is being carried out
should be thoroughly aired from time to time.
Mercury and jewelry
Do not wear jewelry when working with mercury. Pre­­
cious metals will amalgamate when getting in contact
with metallic mercury. This will irreversibly damage your
jewelry!
05
3. Mercury life cycle
06
Goal
•No loss of mercury during use
•100% recovery
•Occupational health and safety
•Environmental protection
Purchase
Use in the
lab
Professional
external
recycling
Collection in
closed
container
Purchase of mercury for polarography
High-quality and high-purity mercury is needed for polarography. Examples of suppliers for mercury are:
Sigma-Aldrich Fluka [7]
• 99.9995%, for polarography, Fluka no. 83359
• 99.9999%, electronic grade, Aldrich no. 294594
Merck [1]
• 99.6%, for polarography, no. 104403
•≥ 99.9999%, suprapur, no. 10440
NQR Nordische Quecksilber Rückgewinnung [10]
•99.999999%, minimum order 500 g
•Shipment only within European Union (EU)
Disposal of used mercury
Mercury can be purified, but extensive laboratory setup
is required and considerable time needed. For this reason,
we recommend to collect waste mercury in a closed container and then send it for disposal or recycling to the
responsible authorities or authorized companies in ac­­cor­
dance with the particular national regulations.
•Do not reuse mercury.
•Only fresh, clean, and dry mercury can be used in
polaro­graphy.
•Separate mercury from a black oxide layer prior to
use if necessary.
Options to dispose used mercury from the lab:
•Recyclers for fluorescent lamps
•Recyclers for batteries
•Suppliers for mercury
Important: Mercury must never be disposed with the
regular municipal waste!
4. General recommendations
General handling rules
•Work under a fume cupboard.
•Do not inhale mercury vapors.
•Avoid contact with the skin.
•Avoid generation of vapors or aerosols.
•Avoid spillage.
General storage rules
•Keep mercury in tightly closed vessels.
•Keep mercury in a well-ventilated place.
•Keep mercury locked up or in an area accessible only.
to qualified and authorized persons.
Personal protective equipment
•Hand protection
-Glove material:
Nitrile rubber
- Glove thickness:
0.11 mm
-Break through time:
> 480 min
•Safety glasses
•Protective measures
- Lab coat
•Hygiene measures
- Immediately change contaminated clothing.
- Apply skin-protective barrier cream.
- Wash hands and face after working with mercury.
- Do not eat, drink, and smoke when using mercury.
07
5. Literature dealing with mercury
[1] Merck Chemicals
http://www.merck-chemicals.com/
[2] Falbe, J. und Regitz, M. 1992
Römpps chemical encyclopedia 9. Stuttgart, New York: Georg Thieme Verlag, 1992. S.3737. ISBN 3-13-734609-6
[3] Euro Chlor – Code of Practice Mercury Housekeeping
Environmental Protection 11, 5th Edition September 1998
http://www.chem.unep.ch/mercury/Sector-Specific-Information/Docs/ENV%20Prot%2011%20Edition%205.pdf
[4] Mutschler, E. 1970
Arzneimittelwirkungen. Stuttgart: Wissenschaftliche Verlagsgesellschaft 1970. S. 379
[5] John Risher, Ph.D., Rob DeWoskin, Ph.D. 1999
Agency for toxic substances & disease registry. Toxicological Profile for Mercury. 1999.
http://www.atsdr.cdc.gov/toxprofiles/tp46.pdf
[6] Strong, L. E. 1972
Mercury Poisoning. J. Chem. Educ. 1972, Bd. 28, 49
[7] Sigma Aldrich
http://www.sigmaaldrich.com/
[8] COWI – Consultancy within Engineering, Environmental Science and Economics, 2008
European Commission. 12 2008
http://ec.europa.eu/environment/chemicals/mercury/pdf/study_report2008.pdf
[9] Carl Roth GmbH + Co KG
http://www.carlroth.com
[10] Avantor Performance Materials formerly Mallinckrodt Baker Inc.
http://www.avantormaterials.com/
Subject to change
Layout by Ecknauer+Schoch ASW, printed by Metrohm AG, CH-9101 Herisau
8.000.5054EN – 2011-05
[11] Nordische Quecksilber Rückgewinnung
http://www.remondis-industrie-service.de/en/ris/spektrum0/produktion/quecksilber/
[12] OSHA
Occupational Safety and Health Guideline for Mercury Vapor.
http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recognition.html
[13] Mercury(II) chloride
Material Safety Data Sheet Mercury(II) chloride.
http://www.sigmaaldrich.com/
www.metrohm.com